The present invention relates to a UAV measuring apparatus which has a laser scanner or a camera mounted on an unmanned aerial vehicle (UAV) and measures a shape of a ground surface and to a UAV measuring system.
In recent years, a method, in which a laser scanner or a camera is mounted on a UAV and a surveying is performed, has begun to spread.
In a UAV measuring system having a laser scanner mounted on the UAV, a position of the UAV is measured by a GNSS (Global Navigation Satellite System) or the like, a ground surface is reciprocally linearly scanned by the laser scanner in a direction orthogonal to a flying direction, a distance to the ground surface and an angle are measured and a shape of the ground surface is determined.
In a UAV measuring system using the laser scanner, an approximately fixed direction is presupposed as a flying direction of the UAV, and a rotation or a tilt of a scanning direction is measured by using an IMU (Inertial Measurement Unit), scan data is aligned based on a measurement result of the IMU and a shape of the ground surface is obtained. A high accuracy is required for the IMU used in this system, and hence an expensive IMU is adopted.
On the other hand, in a UAV measuring system having a camera mounted on the UAV, the ground surface is photographed in such a manner that an overlap of 60% or more can be provided by the camera during the flight, and a shape of the ground surface is determined by a photogrammetry with the use of a photographed image.
In the photogrammetry, tilts or rotations between images are obtained by an orienting operation, by performing an absolute orientation, a shape of the ground surface is determined. The orienting operation between images is a complicated operation, and skills are required for insuring a high accuracy.
Further, there is also a UAV measuring system which has the laser scanner and the camera mounted on a UAV and performs both the ground surface measurement using the laser scanner and the photogrammetry, but this system cannot provide a large synergetic effect, and hence this system is not generalized.